The laryngeal mask airway (LMA) supreme is a relatively new single-use supraglottic airway with modification. The parameters about airway sealing such as oropharyngeal leak pressure (OLP) and leakage volume are important markers of efficacy and safety when using the supraglottic airway. The airway sealing is related to the intracuff pressure of laryngeal mask airway. The aim of this study is to compare the airway sealing of the LMA supreme at various intracuff pressure in children.